What are IC50 and CTC50 in cancer biology?

[TytoAlba95]

Here's an excerpt from a cancer biologyhttps://www.antiox.org/article/78:

MTT assay
The Cytotoxicity of extract of seeds of D. stramonium on MCF7cells was
determined by the MTT assay according to the method of Mosmann.
Cells (1 × 105/well) were plated in 100 μL of medium/well in 96-well
plates. After 48 h incubation the cell reaches the confluence. Then, cells
were incubated in the presence of various concentrations of the extract
in 0.1% DMSO for 48 h at 37°C. After removal of the extract solution,
cells were washed with phosphate-buffered saline (pH 7.4) and 20μL/well
(5mg/mL) of 0.5% 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-tetrazolium
bromide (MTT) in phosphate buffered saline solution was added. After
4 h incubation, 0.04 M isopropanol was added. Viable cells were determined
by the absorbance at 570 nm with reference at 655 nm. Measurements
were performed in 3 times, and the concentration required for
a 50% inhibition of viability (IC50) was determined graphically. Absorbance
at 570 nm was measured with a microplate reader (Bio-Rad, Richmond,
CA), using wells without sample containing cells as blanks. All experiments
were performed in triplicate. The effect of the samples on the
proliferation of human breast cancer cells was expressed as the % cell
viability, using the following formula:

Is CTC50 and IC50 the same, in cancer biology.
According to this book, CTC50 (Common toxicity criteria 50) is the concentration of drug which can kill 50% of total cells/ inhibit 50% of the cell growth.

Here's a link to a paper which shows the calculation of CTC50, which I don't completely understand.

 

[Ygggdrasil]

Based on the definition of CTC50 you have provided, it seems to be equivalent to IC50 (I commonly see IC50 in papers, but I have not seen the term CTC50 used before). The definition of IC50 itself is somewhat flexible and can be somewhat different in different papers depending on the exact methods used in the study.

 

[TytoAlba95]

Based on the definition of CTC50 you have provided, it seems to be equivalent to IC50 (I commonly see IC50 in papers, but I have not seen the term CTC50 used before). The definition of IC50 itself is somewhat flexible and can be somewhat different in different papers depending on the exact methods used in the study.

Thank you. This resolves my problem. :)